The venerable “rabbit ears” TV antennas have become a rarity on the modern TV, which instead typically receives cable TV signals and/or satellite TV signals and/or recorded content from sources such as, e.g., digital video recorders (DVR) and digital video disk (DVD) players through a receiver broadly referred to as a “set top box” (STB). A type of STB is the so-called “set back box” (SBB) which differs from a STB chiefly by being controlled by the same remote control that controls the TV. The term “set box” (SB) is used herein to denote either a STB or a SBB.
With the advent of high resolution digital TVs such as high definition TVs (HDTVs), to extend communication protocols to digital multimedia that includes audio for the purpose of, e.g., playing digital movies and the like, a protocol referred to as High Definition Multimedia Interface (HDMI) has been developed. HDMI is similar to Digital Visual Interface (DVI), a protocol developed primarily for computers that consequently does not envision processing audio data, except that HDMI envisions the use of audio as well as video data and it adds television-related resolutions. Both DVI and HDMI are intended for wired transmission, and HDMI further permits the encryption of digital multimedia using an encryption method known as High-Bandwidth Digital Content Protection (HDCP), which may also be used with DVI.
An advantageous feature of HDMI is that it supports consumer electronics control (CEC), which permits control of the source (SB/DVD player/DVR etc.) and the TV using a single remote control. However, as understood herein, display icon exchange is typically effected between a SB and a TV, and the data exchange when using the HDMI channel is noticeably slow to a viewer in effecting the icon exchange. Accordingly, the present invention recognizes that in addition to a HDMI communication path, a second path such as a universal serial bus (USB) path can be provided which is dedicated to icon exchange as well as to the transmission of certain control commands.
As still further recognized herein, owing to the use of a second path such as a USB channel for the purposes discussed above, it would be possible for someone to plug a personal computer into the TV's USB port and, possibly by spoofing the TV into thinking the PC is a SB, obtain sensitive information on the details of the data exchange between a SB or other content source and a TV. In this way, the protections otherwise afforded by HDCP undesirably might be compromised. Accordingly, the invention herein is provided.